644302494 has 48 divisors (see below), whose sum is σ = 1535539824. Its totient is φ = 195235920.

The previous prime is 644302471. The next prime is 644302501. The reversal of 644302494 is 494203446.

644302494 is a `hidden beast` number, since 644 + 3 + 0 + 2 + 4 + 9 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10512 + ... + 37404.

It is an arithmetic number, because the mean of its divisors is an integer number (31990413).

Almost surely, 2^644302494 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644302494, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (767769912).

644302494 is an abundant number, since it is smaller than the sum of its proper divisors (891237330).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644302494 is a wasteful number, since it uses less digits than its factorization.

644302494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26934 (or 26909 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 644302494 is about 25383.1143479282. The cubic root of 644302494 is about 863.7006984774.

The spelling of 644302494 in words is "six hundred forty-four million, three hundred two thousand, four hundred ninety-four".